(CNN) --To this day, Pete Best has no idea why he was forced out of the Beatles.

Rumors have abounded for more than 40 years. Some say it was because Beatles producer George Martin didn't think Best was a very good drummer.

Other sources accuse Paul McCartney of being jealous of Best's good looks; that Beatles manager Brian Epstein, molding a new image for the band, didn't think Best fit; that John, Paul and George were simply more comfortable with Ringo Starr in the drummer's seat.

To Best, it doesn't matter anymore. It's all old news, and he's moved past it.

"I'm happy with my lifestyle," says the proud husband, father and grandfather in a phone interview from New York. His voice is still rich with Liverpudlian melody. He has spent most of his life in his hometown, where his family name has been highly regarded for decades. (The Best family owned and ran the Liverpool Stadium.) "I don't have time to reflect on [it]."

Nevertheless, Best can still call himself a Beatle, something only six men on the planet -- John, Paul, George, Ringo, Stu Sutcliffe and Pete -- have ever been able to do. He joined the band in 1960, when it played his mother's coffee bar, the Casbah, and was dismissed in 1962, just before the Beatles became the Beatles.

His memories of those early days are collected in a new coffee-table book, "The Beatles: The True Beginnings" (Thomas Dunne/St. Martin's), written by his brother Roag in conjunction with Pete and the other Best brother, Rory.

'The mother of Merseybeat'

The Best brothers' story -- and, for that matter, much of the Beatles' story -- begins with Pete's mother, Mona.

Mona Best was an energetic and striking woman, raised in India as the daughter of a British army officer. During World War II, she married John Best, another army man. They had two sons, and after the war the family moved to John's hometown of Liverpool.

"She's the unsung hero of the story. She's the mother of Merseybeat," Pete Best says.

By the late '50s, with rock 'n' roll creeping into the seaside city and her own teenage children becoming fans, Mona Best decided to create a club where the kids could gather.

She took the empty cellars of the Bests' large house, converted them into meeting spaces, and provided membership cards to hundreds of local teens.

The new club -- the Casbah -- needed a band. Ken Brown, who had helped clean out the cellars, and his pal George Harrison brought in two friends of George's -- the Quarrymen, John Lennon and Paul McCartney. The four helped finish the club's remodeling just before opening night, August 29, 1959, and then they took the stage.

Best, an observer in the early days, was impressed. "It was apparent right from the early stages that they had something," he says. "The harmonies, the sound, it was excellent. There was something magical."

'It was all part of the learning curve'

Best has written a memoir, "Beatle! The Pete Best Story." His recordings with the Pete Best Combo are available on CD, and his early tracks with the Beatles are on "Anthology 1."

The club, in turn, quickly became a Liverpool hot spot. The top bands played there -- the Big Three, Rory Storm and the Hurricanes -- and the lines would start forming hours in advance of the doors opening, says Best. On the biggest nights more than 1,000 people crowded into the warren of rooms.

Meanwhile, the Quarrymen had become the Silver Beatles and, as they prepared to leave for Hamburg, Germany, needed a drummer. Pete, then with a group called the Blackjacks, got the job.

In Hamburg, the band lived in a small room in the back of a movie theater in the city's notorious Reeperbahn district. They'd play for hours, fueled by drink and pills, and developed a hard, tight, leather-jacketed sound. Lennon was about to turn 20; the others were younger. They loved it.

"The Liverpool scene was much more innocent and teenage. The Reeperbahn was hookers and strip clubs, it was great for us," says Paul McCartney in "The True Beginnings."

"It was all part of the learning curve," Best recalls. "It's like, it's rock 'n' roll, let's just enjoy it."

Over the next 18 months, the Beatles came back to Liverpool for a short Casbah residency, recorded with Tony Sheridan in Hamburg, started their residency at the Cavern in downtown Liverpool, acquired Brian Epstein as their manager, and started writing songs by the dozens (Best remembers the creation of "P.S. I Love You" and helping with the arrangement). They were about to break through.

And then, on August 16, 1962, Pete was dismissed.

The Beatles went on to legend. Best hung around the music scene -- he had his own combo in the mid-'60s -- but eventually left the business, working in a bakery and later as a civil servant.

In 1988, however, he was encouraged to put a band together by some old friends. Roag manages the group; Pete does the drumming with his son. He enjoys it immensely.

It was apparent right from the early stages that they had something. The harmonies, the sound, it was excellent. There was something magical.

-- Pete Best on first hearing the combo that became the Beatles

"Our lead singer is like a young McCartney," he says. "It's a very powerhouse sound."

He stays in touch with some of the old crowd, particularly Beatles road manager and friend Neil Aspinall, who had a long-term relationship with Mona in the mid-'60s that produced Roag.

Mona Best died in 1988, but the Beatles -- particularly Lennon -- never forgot her. They gave her gifts, and she lent them some of her things, such as the medals that appear on the "Sgt. Pepper" album cover.

In the past couple years, the brothers have taken over their old home and renovated the Casbah. It's a part of history now, and the original design and furnishings -- much of it done by the Beatles -- is still intact. The club will soon be open for tours and entertainment. Merseybeat will reign again.

"It's not just going to be a museum," says Pete. "We've resurrected the Casbah from the ashes."